Industrial process heating (IPH) demand in the U.S. is largely met by the consumption of fossil fuels. Much of this demand is for hot water and steam at temperatures below 300° C, a thermal regime that is aligned to solar thermal and photovoltaic (PV) technologies. The potential for solar energy systems to satisfy such IPH demand was examined by researchers from Northwestern University and the U.S. National Renewable Energy Laboratory (NREL).

The analysis of county-level and industrial end user process heat demand data for 2014, which are accessible in an interactive viewer, focused on prospective IPH demand contributions from non-concentrating collectors, concentrating collectors and PV-connected technologies. Factors considered include available land area, hourly solar resource, IPH temperatures and hourly IPH demand.

About 11.2 quadrillion Btu of fuels were combusted to meet U.S. IPH demand in 2014, equivalent to 11% of national total primary energy use and about 28% of all the energy used in the residential and commercial sectors combined, with the most significant demand associated with petroleum refining. When combined with thermal energy storage, parabolic trough collectors offer the greatest opportunity in terms of distribution over geography and time, but also in terms of applicable IPH demands. This solar option can displace nearly 2,500 trillion Btu of combustion fuels, which corresponds to about 15% of all industrial combustion carbon dioxide emissions.

Opportunities for solar penetration in this arena are limited by the technology’s ability to meet IPH demands that occur when sunlight is not available, particularly for industries that operate around the clock. Additional research is needed to develop higher-resolution IPH demand data and to explore thermal energy storage options and sizes to minimize thermal losses.

Applications of IPH matched to relevant solar technologies. Source: NREL